Mentos in Diet Coke

Amelie
400px-Diet_Coke_Mentos.jpg
The reaction formed by mentos in Diet Coke


Introduction:

The purpose of this experiment was to see if the acid in Coke (regular or diet) would affect the reaction when you add it with Mentos through both qualitative and quantative data. The independent variable was the concentration of Coke (or acid) in each of the solutions: 500 ml pure Diet Coke, 400 ml Diet Coke and 100 ml water, 300 ml Diet Coke and 200 ml water, and 200 ml Diet Coke and 300 ml water. I formed a procedure (noted as "original procedure" below) to obtain quantative data to prove the results of the experiments. However, the four solutions above proved to be all failures as no reaction occured. Therefore, I changed my experiments, to all unopened bottles of 600 ml pure, regular Coke and noted down the reactions only in qualitative form. Even though most of my trials appeared not effective, I was still able to find many conclusions and concepts noted to my experiment, shown in my evaluation.

Materials:

  • 5 600 ml bottles of Coke
  • at least 5 pieces of Mentos for each experiment
  • Graduated cylinder
  • Large beaker
  • 1 sheet of paper or a test tube about the circumference of a piece of Mentos
  • Meter stick
  • 600 ml of water

Original Procedure:

  1. Create your 5 solutions by measuring and adding necessary amounts of Diet Coke and water
    • 500 ml pure Diet Coke/Pepsi
    • 400 ml Diet Coke and 100 ml water
    • 300 ml Diet Coke and 200 ml water
    • 200 ml Diet Coke and 300 ml water
    • also try, 600 ml of only Diet Pepsi, reclose after adding Mentos with a pierced cap
  2. Place one bottle of Diet Coke near a wall so the eruption will show on the wall
  3. If you are using a sheet of paper, roll it up so that is looks like a funnel wide enough so that the Mentos candy can be inserted.
  4. Place 5 Mentos candies inside the test-tube or paper funnel so that they're stacked one on top of the other in a single column.
  5. Place the index card over the mouth of the test-tube or paper funnel on the top end. Flip the test tube/funnel over so that the index card stops the candies from falling out.
  6. Open the bottle of Diet Coke
  7. Place the Mentos, which are still in from the test tube, over the bottle opening, index card down
  8. Quickly remove the index card so that the candies will fall into the bottle in one smooth motion and stand back.
  9. Once the reaction is over, measure how high the Diet Coke erupted by measuring the highest splash of Diet Coke shown on the wall
  10. Then measure the liquid still in the bottle of Diet Coke
  11. Record your measurements and observations
  12. Redo steps 2 - 11 for the rest of your experiments with the different solutions of Diet Coke and water

Observations of Above Procedure:

The experiments have not been working. Since I was unable to find the actual Mentos, I first tried out Mentos chewing gum in 500 ml of pure Diet Pepsi. There was no eruption except for possible fizzing, even after I added 5 pieces of Mentos. Later, when I emptied out the bottle, I found that the shell had disintegrated and separated (?) into little pieces while the rest of the candy was still left at the bottom.

On the second day of experimenting, I tried 600 ml of pure Coke, which I first shook and then added five Mentos with some activated charcoal to see if my solution would react at all. It did react but it was more of a foaming just over the opening of the bottle. This was the most resulting experiment I had conducted but since it was just to make sure that I would get any reaction at all when adding Mentos to soda. I then tried Diet Pepsi and added five mentos with the rest of the activated charcoal, about 100 ml. There was a reaction this time, like with the Coke but there was a bit less foaming. From these two experiments, I concluded that using Coke would be much more productive and so I will continue with mint Mentos and Coke for my following experiments. I'm not sure whether I can experiment with the concentration of my solutions since they might not all react. Then again, that may be the answer to the experiments (less soda concentration results to a smaller reaction.)


co2molecule.jpg
water_molecule_full_size_landscape.jpg
Water molecule (H2O)


rough_mentos.jpg
This image shows the roughness of the mint mentos (top and bottom left) compared to fruit mentos (top and bottom right.) The website linked here explained that the more space available will create more bubbles.

Evaluation

- Amelie

Additional Websites:

An ABC News Report
NewScientist Experiment Explained
Reeko's Science Experiments

Bibliography:

Research:

Basic Procedure

Images:

"The reaction formed by Mentos and Diet Co
Carbon dioxide molecule
Water molecule
Roughness of Mentos

Videos:

Mentos and Diet Coke Experiment